Electronic musical instruments such as synthesizers and the like can generate tones with various kinds of tone colors. When performance of a natural musical instrument is imitated by an electronic musical instrument, it is necessary to make the tone colors to be faithfully imitated to tone colors of the natural musical instrument. In addition, the performer needs to understand characteristics peculiar to the musical instrument while operating user interfaces of the musical instrument (such as, for example, the keyboard, the pitch-bend lever, the modulation lever, the HOLD pedal and the like) during performance. Therefore, when a performer attempts to imitate performance of a certain musical instrument, using an electronic musical instrument, the performer needs to understand the characteristics of the musical instrument to be imitated and needs high-level skills in performance technique to make full use of the user interfaces to adequately imitate the characteristics of the musical instrument during performance.
When a musical instrument that is capable of generating multiple tones at the same time, such as a guitar, is imitated by keyboard operation on an electronic musical instrument, performance in a poly mode, by which a plurality of tones can be generated at the same time, is desirable. However, for example, a string musical instrument such as a guitar is characterized due to its structure in that, while multiple tones can be generated as described above, a tone that is being generated on one string is silenced when the same string is plucked. Therefore, when a string musical instrument such as a guitar is imitated by keyboard operation of an electronic musical instrument, the performer needs to pay attention to avoid generating multiple tones concurrently that would be on the same string of the instrument being imitated in poly mode, such as a guitar. This requires high-level performance technique.
Japanese Patent No. 3738117 describes a technology to switch between a polyphonic assignment and a monophonic assignment depending on the strength of a key depression.
However, the technology described in Japanese Patent No. 3738117 cannot imitate the characteristic of a string musical instrument such as a guitar.